Benchmark: Javascript string.endsWith vs string.slice and triple equal

Script Preparation code:

function compareEndsWith(val, comparator) {
  return val.endsWith(comparator)
}
function compareSliceMethod(val, comparator) {
  const thingToCompare = val.slice(-comparator.length)
  return thingToCompare === comparator
}

Tests:

endWith
const value = Math.random().toString().padEnd(20,'0'); const ending = "asdf" compareEndsWith(value, ending)
slice
const value = Math.random().toString().padEnd(20,'0'); const ending = "asdf" compareSliceMethod(value, ending)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
endWith
slice

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

I'd be happy to help you understand the JavaScript benchmark on MeasureThat.net.

**Benchmark Overview**

The benchmark compares two ways to check if a string ends with a specific suffix: `string.endsWith()` and `string.slice() + ===`. The benchmark is designed to measure which approach is faster, more efficient, and possibly more accurate for this specific use case.

**Options Compared**

Two options are compared:

1. `string.endsWith(comparator)`: This method checks if the string ends with the specified suffix (`comparator`).
2. `string.slice(-comparator.length) === comparator`: This approach uses the `slice()` method to extract a substring from the end of the original string, and then compares it directly to the comparator using the `===` operator.

**Pros and Cons**

1. **string.endsWith(comparator)**:
	* Pros: More readable, concise, and efficient (as it's implemented in native code).
	* Cons: May not be as performant for very large strings due to its dynamic nature.
2. **string.slice(-comparator.length) === comparator**:
	* Pros: Can be more performant for large strings, as it avoids the overhead of a dynamic method call.
	* Cons: Less readable and more verbose, which can make the code harder to maintain.

**Library**

There is no library explicitly mentioned in this benchmark. However, `string.endsWith()` is an intrinsic JavaScript method that's implemented by most modern browsers and Node.js environments.

**Special JS Feature or Syntax**

This benchmark does not use any special JavaScript features or syntax beyond what's standard in JavaScript (ECMAScript).

**Benchmark Preparation Code**

The preparation code defines two functions:

* `compareEndsWith(val, comparator)`: This function checks if the string `val` ends with the specified suffix (`comparator`) using the `endsWith()` method.
* `compareSliceMethod(val, comparator)`: This function uses the `slice()` method to extract a substring from the end of the original string and compares it directly to the comparator using the `===` operator.

**Other Alternatives**

In theory, other approaches could be used to check if a string ends with a specific suffix, such as:

* Using a regular expression: `RegExp.prototype.test(val, new RegExp(`^.*${comparator}$`, 'g'))`
* Implementing a custom function using bitwise operations and string manipulation
* Using a library like Lodash or Underscore.js

However, these alternatives are not part of the benchmark and may not be as efficient, readable, or maintainable as the two options being compared.

I hope this explanation helps! Let me know if you have any further questions.

Related benchmarks:

Javascript string.endsWith vs string.slice and triple equal (version: 0)

Comparing performance of: endWith vs slice

Created: 3 years ago by: Guest

Jump to the latest result

endWith

slice

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):